YS/T 3005-2011Methods for sampling and sample preparation of flotation gold concentrates (English PDF)

4.1 The standard deviation (sigmaw) of the mass fraction between the increments in

a lot indicates the quality fluctuation of the gold concentrate. The quality

fluctuations of gold concentrates are divided into three categories. high,

medium, low (see Table 1).

4.3 If the quality fluctuation of the gold concentrate of the lot is sigmaw >= 5.0 or

otherwise it is mixed by foreign inclusions, it is negotiated between the supplier

and the purchaser or otherwise no sample is taken.

4.4 The total precision for sampling of gold concentrate of a lot is 2% of the

gold's mass fraction.

4.5 For the first sampling of gold concentrate and the change of sampling and

sample preparation method, it shall follow the requirements of Appendix C to

carry out precision test of calibration sampling.

4.6 The sampling and sample preparation plan of gold concentrate shall be

confirmed by the relevant parties.

4.7 Gold concentrates that do not meet the requirements of YS/T 3004 shall not

be sampled or be negotiated between the supplier and the purchaser.

4.12 The operation of sampling and sample preparation shall comply with the

relevant safety specifications.

5.1 Sampling tools

5.1.1 Sampling brazing bar (see Figure 1), the specification size of which shall

meet the requirements for the amount of sample taken.

5.2 Sampling procedure

5.2.1 Weigh the mass of the delivered gold concentrate. If the gold concentrate

is mixed with rain or snow water or visible water, it shall be dewatered before

weighing.

5.2.2 Develop a sampling plan, which shall include the following.

5.2.3 Check the sampling facility equipment and appliances.

5.2.4 According to the sampling plan, take sample and make record. Place the

increment taken into a container with lid or plastic sample bag.

5.3 Increment mass

The mass of the increment taken shall be not less than 300 g. The coefficient

of mass variation (CV) shall be not more than 20%.

5.4 Combination of increments

5.5 Sampling method

5.5.1 Systematic sampling

5.5.1.1 In the course of movement of bulk gold concentrates during handling or

weighing, take increment based on certain mass interval or time interval.

5.5.1.5 It shall select the sampling device of appropriate size to collect the full-

width, full-thickness gold concentrate stream.

5.5.2 Truck sampling

5.5.2.1 From the motor vehicles, trains, bins which are loaded with gold

concentrates, take the increment.

5.5.2.2 The material surface of the gold concentrate shall be flat. Based on the

number of increments as specified in Table 1, calculate the uniform distribution

points.

5.5.3 Sampling from stockyard

5.5.3.1 Unload a lot of gold concentrate in a stockyard that is spacious, clean,

level, free from external contamination.

5.5.3.2 After mechanically or manually mix it evenly, flatten the pile to make its

height be less than 1 m.

5.5.4 Sampling from bags

5.5.4.1 When handling the bagged gold concentrate, take the increment. Use

the brazing bar to perpendicularly penetrate the packaging bag.

5.5.4.2 When the type of quality fluctuation is unknown, take at least one

increment per bag.

6.1 Sample preparation equipment and tools

6.1.1 Grinder or rod mill.

6.1.2 Constant-temperature drying oven.

6.1.3 Non-absorbent division plates, stainless-steel cross-split plates, baffles,

rubber.

6.1.8 Sample container and component sample bag.

6.2 Sample preparation requirements

6.2.1 Sample preparation includes a series of operations such as mixing, drying,

grinding, division. It shall prevent contamination and chemical composition

changes of the sample.

6.3 Sample preparation procedure

6.3.1 Weigh and check the mass of the lot sample and subsample.

6.3.2 Establish the sample preparation plane, which shall include the following.

6.3.3 Check the cleaning facilities and equipment.

6.3.4 According to the plan, prepare specimen and make record.

6.4 Mixing method

6.4.1 Rolling method

Place the sample on a clean sample-mixing rubber. Lift the opposite corners of

the rubber to perform up-and-down movement, to allow the sample to roll over

the centerline of the rubber. Use the same method to repeat operations for the

other pair of opposite corners for at least 5 times, to mix the sample uniformly.

6.5 Division method

6.5.1 Quadruple

Flatten the top of cone. Use the cross-split plate to divide the sample into four

equal portions from top down. Discard half of the diagonal sample. Retain the

other half of sample. Use the pile cone method to mix the retained sample

uniformly. Repeat the above operation, to divide it to the required amount.

7.1 The shelf life of chemical composition specimen is three months.

7.2 The sample bag shall be clearly marked of the following.

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